[0001] The invention relates to a device for programming a video recorder using time and
date information contained in a teletext page, which device comprises
- an input terminal for receiving the information contained in a teletext page,
- a date detector for detecting a date present in the information of the teletext
page,
- a time detector for detecting a time present in the information of the teletext
page, and to a video recorder comprising the device. A device of this type is decribed
in the magazine "Funkschau", no. 7, 1989, pp. 62-65.This device is a VPT (Videorecorder-Programmierung
mit Fernseh-Text) programming device of a video recorder.
[0002] The prior-art device has the drawback that during programming it happens quite often
that information from the teletext page is misinterpreted, so that a wrong date or
a wrong time is programmed.
[0003] It is an object of the invention to provide two steps enabling a video recorder to
be programmed more accurately.
[0004] In order to implement the first step the device in accordance with the invention
is characterized in that the time detector is adapted to detect time information from
at least four consecutive characters in the information of the teletext page, in that
in addition the time detector is adapted to detect four consecutive characters in
the form of exactly four consecutive digits in the information of the teletext page,
and in that the time detector is adapted to accept the four consecutive digits as
a time if the time detector has not detected any time information in another form
than exactly four consecutive digits in the information of the teletext page.
[0005] In order to implement the second step the device in accordance with the invention,
which device is adapted to assign a date detected by the date detector to a time detected
from a teletext page by the time detector, is characterized in that if a time subsequently
detected from the same teletext page by the time detector represents an instant prior
to the previously detected time the device is adapted to assign a date incremented
by one day to the detected time.
[0006] The invention is based on the recognition of the fact that the device should also
perform to an optimum extent when a video recorder is programmed by means of teletext
pages not composed in accordance with a specific standard such as for example the
VPT standard.
[0007] A possible standard is described, for example, in the EBU/UER proposal "Specification
of the domestic video programme delivery control system (PDC)" of March 1989.
[0008] In accordance with this standard the instants at which programs begin are expressed
as follows in the teletext page: 20.00 for 8 pm. and 09.30 for an instant before 10
a.m. In a non-standard VPT teletext page the time information may also be expressed
differently, for example 20.00 for 8 p.m. and 9.30 or 9:30 or 09:30 for nine-thirty
a.m.
[0009] This means that the time detector should be adapted to detect at least four consecutive
characters in the information of the teletext page. If these characters take the form
of one or two digits followed by a . (point) or a : (colon), which is followed by
two further digits, the values for the three or four digits of course being such that
they can denote a time, the time detector will detect the information as being a time.
[0010] A problem arises if a teletext page contains time information in a form as inserted
in the BBC teletext pages, namely in the form of 2000 for the time 8 p.m. Simply detecting
exactly four consecutive digits in a teletext page does not provide a solution because
the teletext information may include years (for example "the film was made in the
year 1955"), which may easily be misinterpreted as times (in the present example the
time five to eight p.m.).
[0011] The first step now enables time information in a form as included in the teletext
information by, for example, the BBC to be detected. It is then assumed that such
a teletext page does not contain any time information expressed in a manner other
than described hereinbefore.
[0012] Thus, a teletext page is examined for the presence of standard time information and
time information which deviates slightly therefrom, and for exactly four consecutive
characters in the form of four digits.
[0013] If the time detector detects four consecutive characters in the form of four digits
acceptance or rejection of the four digits as a time will depend on whether the time
detector also detects time information in a different form in the teletext page. If
no time information in another form is found in the teletext page the four digits
will be accepted as a time. In the other case they will be rejected.
[0014] Another problem which may occur in the case of non-standard teletext pages is the
following. For programming on the basis of the information in a teletext page it is
necessary to examine the teletext page first for the presence of date and time information.
If the date detector detects a date and subsequently the time detector detects a time,
this time is stored as the starting time of a program together with a data in a memory
row.
[0015] If subsequently a time corresponding to the beginning of a second program is detected
this time is stored as the starting time of the program together with the date in
a second storage row. Moreover, the second time is stored in the first memory row
as the end time of the first program. This proceeds in the same way for subsequent
times in the teletext page.
[0016] However, television programs specified on a teletext page for a specific day (date)
may continue until after midnight.
[0017] Thus, a program which begins after midnight would be given an incorrect date in accordance
with the method described above.
[0018] However, the second step ensures that nevertheless the correct date is assigned to
the starting time for programs starting after midnight.
[0019] Embodiments of the invention will now be described in more detail, by way of example,
with reference to the drawings. In the drawings
Fig. 1 shows an embodiment of the device,
Fig. 2 shows a teletext page,
Fig. 3 shows the contents of the time and date memory in the device,
Fig. 5 shows the device of Fig. 1 in more detail,
Fig. 6 shows the data detector of the device in Fig. 1, in more detail, and
Fig. 7 shows the time detector of the device in Fig. 1 in more detail.
[0020] Fig. 1 shows a first embodiment of the device, which has an input terminal 1 for
receiving the teletext information. The information is applied to a date detector
2 and a time detector 3. A date detected from the information of a teletext page by
the date detector 2 is transferred to an output 4. A time detected from this information
by the time detector 3 is transferred to an output 5. The outputs 4 and 5 of the detectors
2 and 3 respectively are coupled to inputs 6 and 7 of a memory 8. The date detector
2 can detect a date expressed in different forms from in the information of a teletext
page. Possible forms of the date are:
24/8/
24.08
24-8-
24 Aug.
When it is known that the date in the teletext page is possibly specified in yet another
manner, this can of course be allowed for in the detection by means of the detector
2. If the teletext page does not contain any date information, the date detector 2
cannot find any date information in the page. In that case the date detector can use
the internal date of the video recorder as being the date.
[0021] The date thus detected by the detector 2 is available on the output 4 and is applied
to the input 6 of the memory 8.
[0022] The time detector 3 can detect a time expressed in one of the following forms from
the information of a teletext page:
uv.xy
uv:xy
v.xy
v:xy
u (if present), v, x and y being characters in the form of digits, the number uv complying
with 00 ≦ uv ≦ 24 and the number xy complying with: 00 ≦ xy ≦ 59. If there is no digit
u this means that v complies with:0 ≦ v ≦ 9.
[0023] The above notations for the time may be standard notations. The detector 3 now detects
six or seven consecutive characters, checks whether the first and the last character
are not digits, and checks whether the other characters satisfy one of the above notations
and requirements with regard to uv, v and xy. In the case of compliance the time thus
detected is transferred to the output 5.
[0024] How a video recorder is programmed will now be described with reference to Figs.
2, 3 and 4. By way of example Fig. 2 shows diagrammatically a teletext page as may
be displayed on a television screen. The page contains the program transmitted by
a certain station on August 24, 1989.
[0025] In a first step the device searches the teletext page for the date and time information.
The detector 2 detects 24 August as the date and transfers the date to the output
4. The time detector 3 detects time information which complies with one or more standard
notations.
[0026] Under the influence of a control unit 10, which for this purpose supplies a control
signal to the detector 3
via the line 11 the detected time 20.00 is transferred to the output 5.
[0027] Under the influence of a control signal applied to the memory 8
via the line 12, this time is stored as the starting time in a storage location r₁ (row
1), c₁ (column 1) of the memory 8. Likewise, the date is stored in the storage location
r₁, c₄ (column 4) and the cursor position on the display screen, corresponding to
the display screen coordinates of the location p₁, directly after the time "20.00"
on the screen, is stored in the storage location r₁, c₃ (column 3) in the memory 8.
Fig. 3 represents diagrammatically the contents of the memory 8.
[0028] Subsequently, under the influence of a control signal from the control unit 10, the
second time "20.30" is transferred to the output 5. This time is stored as the starting
time of the second program in the storage location r₂, c₁ and as the end time of the
first program in the storage location r₁, c₂ in the memory 8. The cursor position
p₂ (see Fig. 2) is stored in the storage location r₂, c₃ in the memory 8. Moreover,
the date is stored in the storage location r₂, c₄, see Fig. 3.
[0029] Subsequently the third time "22.00" is stored as the starting time of the third program
in the storage location r₃, c₁ and as the end time of the second program in the storage
location r₂, c₂. The date and the cursor position are stored in the storage locations
r₃, c₄ and r₃, c₃.
[0030] This continues until the time "00.30" appears on the output 5 of the detector 3.
A detector 13, which has an input coupled to the output 5 of the detector 3, detects
that the time "00.30" is an instant prior to the time "22.30" supplied by the detector
3. The detector 13 now supplies a control signal to an output 14, which is applied
to the detector 2
via a control signal input 15. Under the influence of this control signal the detector
2 now generates a date incremented by one on its output 4:
i.e. the date August 25. Under the influence of the controls signals applied to the memory
8 by the control unit 10 the time "00.30" is now stored as the starting time in the
storage location r₅, c₁ and as the end time in the storage location r₄, c₂. The cursor
position is stored in the storage location r₅, c₃ and the date incremented by one
is stored in the storage location r₅, c₄. Finally, if this can be derived from the
teletext page, the end time "01.00" of the fifth program is stored in the storage
location r₅, c₂.
[0031] If the end time cannot be derived from the teletext page, which means that the last
row on the teletext page of Fig. 2 is absent, the time detector 3 can generate an
end time which is, for example, three hours later than the starting time of the last
program. This end time can then be stored in the storage location r₅, c₂ as a default
value. The memory 8 may comprise more columns for the storage of information relating
to VPS (Video-Programm-System) as currently used in Germany, cf. the above mentioned
article in Funkschau.
[0032] The video recorder is now programmed as follows. By means of the cursor a program
as appearing on the teletext display can now be selected, for example, the second
program which is a talkshow and which immediately follows the 8 o'clock news. By applying
a programming control signal, which can be applied to the video recorder for example
via the remote control unit and which, in Fig. 1, is applied to the memories 8 and 9
via the terminal 17, the second row of the memory 8, which may contain VPS information
can be read out and this information can be stored in the programming memory 9. In
a similar way the video recorder can be programmed to record the fourth program (the
film) and the fifth program (the news). By way of example, the contents of the programming
memory 9 is shown diagrammatically in Fig. 4.
[0033] On the basis of the data in the programming memory 9 the video recorder can subsequently
record the programmed items automatically.
[0034] Fig. 5 shows the device in Fig. 1 in more detail, in particular the detector 13 in
Fig. 1. The detector 13 comprises a memory 20 and a comparator 21. The input of the
detector 13 is coupled to the input of the memory 20 and to an input of the comparator
21. The output of the memory is also coupled to a (second) input of the comparator.
The output of the comparator 21 is coupled to the outpout 14 of the detector 13.
[0035] If a time, such as the time "22.30" which is the starting time of the film, is transferred
to the output 5 of the detector 3 this time is stored not only in the memory 8 under
the influence of a control signal
via the line 12 but also in the memory 20 under the influence of a control signal applied
to the memory 20
via the line 22.
[0036] The time "22.30" is stored in the memory 20 with a certain delay, after the date
has been stored in the memory 8 in the storage location r₄, c₄ corresponding to the
fourth program.
[0037] Subsequently, the time "00.30" appears on the output 5. The time "22.30" stored in
the memory 20 is applied to the input 23 of the comparator 21 and the time "00.30"
is applied to the input 24 of this comparator 21.
[0038] The comparator 21 detects that the time applied to its input 24 is an instant prior
to the time applied to its input 23. On the basis of this the comparator 21 supplies
a control signal, which is applied to the output 14. In response to this control signal
the date detector 2 supplies a date corresponding to the detected date incremented
by one day.
[0039] Fig. 6 shows an example of a date detector 2 by means of which this can be realised.
The detector 2 comprises a detection unit 30 which can detect a date. This date is
subsequently stored in a memory 31. The detector 2 comprises a second memory 32 in
which a date incremented by one day is stored. The outputs of the memories 31 and
32 are coupled to terminals
a and
b respectively of switching means S₁, in the form of a controllable switch.
[0040] In the normal situation,
i.e. for times before midnight, the switch S₁ is in position a-c. However, if the time
"00.30" is applied to the output 5, the comparator 21, as stated hereinbefore, generates
the control signal, which is applied to the switch S₁
via the control signal input 15. Under the influence of this control signal the switch
S₁ is set to position b-c, so that the date incremented by one is supplied to the
output 4.
[0041] It is to be noted that in a teletext page as shown by way of example in Fig. 2, which
is composed in conformity with the VPT standard, the date of August 25 is inserted
in the teletext information of this page, namely between the row with the film of
22.30 and the row with the new of 00.30. This date need not necessarily be displayed
on the screen. The date detector 2, however, is capable of deriving this date from
the teletext information of this page and storing it in the memory 31. Moreover, upon
detection of this second date the line from the control signal input 15 to the switch
S₁ is interrupted (not shown), so that the switch S₁ cannot change over to position
b-c.
[0042] Fig.7 shows the time detector 3 in Fig. 1 in more detail, which detector bears the
reference numeral 3′. The detector 3′ comprises a unit 40 for detecting time information
included in the teletext page in a manner as described hereinbefore. The detector
3′ further comprises a unit 41 which is adapted to recognise exactly four consecutive
characters in the form of digits in the teletext information. The number uv should
comply with: 00 ≦ u ≦ 24 and the number xy should comply with 00 ≦ x ≦ 59. If these
requirements are met for four consecutive characters, the information of these four
characters is always detected as a time. It is obvious that neither the character
preceding nor the character following these four characters should be a digit.
[0043] The reason that at least four characters in the form of a digit are detected and
not at least three characters in the form of digits is that teletext the page numbers
are expressed in three digits. A page number could then be identified as a time, which
is of course undesirable.
[0044] An entire teletext page is searched for the presence of time information. Times detected
by the unit 40 are stored in the memory 42 and times detected by the unit 41 are stored
in the memory 43. Outputs of the memories 42 and 43 are coupled to the terminal
a and
b respectively of switching means S₂, in the form of a controllable switch. The terminal
c of the switch S₂ is coupled to the input 5 of the detector 3′.
[0045] If the unit 40 has not detected any time information in conformity with one of the
standard notations the unit 40 will apply a control signal to the switch S₂
via a control signal output 44 in order to set this switch to position b-c.
[0046] Time information detected by the unit 41 and stored in the memory 43 can now be applied
to the output 5
via the switch S₂.
[0047] If the unit 40 detects a time a second control signal is generated via the output
44 in such a manner that the switch S₂ is set to position a-c. The times detected
by the unit 40 and stored in the memory 42 can now be transferred to the output 5.
[0048] It is to be noted that the invention is not limited to the embodiments disclosed
herein. The invention also relates to those embodiments which differ therefrom in
respects which are not relevant to the invention.
The object of the invention is to use one or both steps in a video recorder, so that
an improved programming of the video recorder can be achieved. The step(s) may be
implemented in hardware, as described with reference to the Figures. Another possibility
is to realise the step(s) by means of software.
1. A device for programming a video recorder using time and date information contained
in a teletext page, which device comprises
- an input terminal for receiving the information contained in a teletext page,
- a date detector for detecting a date present in the information of the teletext
page,
- a time detector for detecting a time present in the information of the teletext
page,
characterized in that the time detector is adapted to detect time information from
at least four consecutive characters in the information of the teletext page, in that
in addition the time detector is adapted to detect four consecutive characters in
the form of exactly four consecutive digits in the information of the teletext page,
and in that the time detector is adapted to accept the four consecutive digits as
a time if the time detector has not detected any time information in another form
than exactly four consecutive digits in the information of the teletext page.
2. A device as claimed in Claim 1, which device is adapted to assign a date detected
by the date detector to a time detected from a teletext page by the time detector,
characterized in that if a time subsequently detected from the same teletext page
by the time detector represents an instant prior tp the previously detected time the
device is adapted to assign date incremented by one day to the detected time.
3. A device as claimed in Claim 2, characterized in that the device comprises a comparator
for comparing with each other a first time detected from a teletext page and a second
time subsequently detected from the teletext page, in that the comparator is adapted
to supply a first control signal to an output if the second time represemts an instant
later than the first time and to supply a second control signal if the second time
represents an instant prior to the first time, in that the output of the comparator
is coupled to a control signal input of the date detector, and in that the date detector
is adapted to transfer the detected date to an output when the first control signal
is applied and to transfer the date incremented by one day to the output when the
second control signal is applied.
4. A device as claimed in Claim 1, 2 or 3, characterized in that the time detector
comprises a first detection unit for detecting exactly four consecutive characters
in the form of digits in the information of a teletext page, a second detection unit
for detecting time information in the teletext page in another form than exactly four
consecutive digits, in that an output of the first detection unit is coupled to a
first terminal of controllable switching means, an output of the second detection
unit is coupled to a second terminal of the controllable switching means, in that
the third terminal of said switching means is coupled to an output of the time detector,
in that the second detection unit comprises a control signal output which is coupled
to a control signal input of the switching means, in that the second detection unit
is adapted to generate a first control signal upon detection of time information in
another form than exactly four consecutive digits in a teletext page, and to generate
a second control signal in the absence of the last-mentioned time information in a
teletext page, and in that the switching means are adapted to couple the first terminal
to the third terminal under the influence of the second control signal and to couple
the second terminal to the third terminal under the influence of the first control
signal.
5. A video recorder comprising a device as claimed in any one of the preceding Claims.